(4) (x)=(x)^3-(x)^2-x+1 满足 () .-|||-(A)在 (-infty ,-dfrac (1)(3)] 内单调递增 (B)在 [ dfrac (1)(3),+infty ) 内单调递减-|||-(C) x=1 处取得极大值 (D)在 [ dfrac (1)(3),+infty ) 内为凸函数

lim _(xarrow infty )(3x-sqrt (a{x)^2-x+1})=dfrac (1)(6), 则 a=

)求下列极限:-|||-(1) lim _(xarrow 1)dfrac ({x)^2-x+1}({(x-1))^2} =-|||-(3) lim _(xarr

(x)=dfrac (1)(3)(x)^3-(x)^2-8x+1的单调增加区间是( )(x)=dfrac (1)(3)(x)^3-(x)^2-8x+1(x)=d

函数(x)=dfrac (1)(3)(x)^3+dfrac (1)(2)(x)^2的单调递增区间是( )A．(x)=dfrac (1)(3)(x)^

1、曲线 =3(x)^4-4(x)^3+1 的凸区间是 () ;-|||-(A) (-infty ,0) (B) (1,+infty ) (C) (dfrac

17、单选 lim _(xarrow infty )dfrac (sin 3x+2x)(sin 2x-3x)-|||-A dfrac (1)(3)-|||-B

(int )_(-infty )^+infty (x)^2(e)^-a(x^2)dx=dfrac (1)(2)sqrt (dfrac {pi )({a)^3}}

(3) lim _(xarrow infty )((dfrac {2x+3)(2x+1))}^x+1

(3) lim _(xarrow infty )((dfrac {2x+3)(2x+1))}^x+1;

(3) lim _(xarrow infty )((dfrac {2x+3)(2x+1))}^x+1;